Flow-Mediated Dilation of Human Coronary Arterioles

人冠状动脉的血流介导扩张

• 批准号: 7333272
• 负责人: David D. Gutterman
• 金额: $ 36.78万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7333272
• 关键词: Actins; Address; Antimycin A; Antioxidants; Binding; Biological Assay; Blood Vessels; Cell physiology; Cells; Chemical Stimulation; Complex; Coronary; Coronary Circulation; Coronary artery; Coronary heart disease; Coupling; Cytochalasin D; Cytochrome P450; Cytoskeleton; Cytosol; Data; Dilator; Disruption; Electron Transport; Electron Transport Complex III; Elements; Elevation; Endothelial Cells; Endothelium; Event; F-Actin; Figs - dietary; Filament; Focal Adhesion Kinase 1; Future; Gelsolin; Generations; Heart; Heme; Human; Hydrogen Peroxide; Immunohistochemistry; Inner mitochondrial membrane; Laboratories; Link; Measures; Mechanics; Mediating; Metabolism; Microtubules; Mitochondria; Mixed Function Oxygenases; Molecular; Mucous Membrane; Nitric Oxide; Nitric Oxide Donors; Nocodazole; Oxidation-Reduction; Oxidative Stress; Paclitaxel; Pathway interactions; Patients; Peroxonitrite; Physiological; Play; Production; Prostaglandins; Qi; Reaction; Reactive Oxygen Species; Relaxation; Reporting; Research Personnel; Resistance; Respiration; Respiratory Chain; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Small Interfering RNA; Smooth Muscle Myocytes; Source; Superoxide Dismutase; Superoxides; Surface; System; Testing; Thinking; Tissues; Variant; Vasoconstrictor Agents; Vasodilation; arteriole; autocrine; base; catalase; depolymerization; detector; inhibitor/antagonist; jasplakinolide; novel; polymerization; prevent; programs; research study; shear stress; vascular bed

Shear stress acting on endothelial cells produces vasodilation. This is arguably the most physiologically important endothelial mechanism of dilation and occurs in virtually every vascular bed. Recent data from our laboratory indicate that flow-mediated dilation (FMD) occurs in coronary arterioles from patients with coronary disease however it operates through a novel mechanism involving endothelial production of reactive oxygen species (ROS) including hydrogen peroxide (H2O2). Surprisingly the mitochondrial respiratory chain plays a necessary role in FMD in the human heart, however it is not known how mitochondria are involved in the transduction of mechanical shear stress on the surface of the endothelium to elicit dilation. Our overall hypothesis is that shear acting on endothelial cells through attached cytoskeletal elements stimulates release from the mitochondria ofH2O2, an endothelial derived hyperpolarizing factor (EDHF). We shall test this hypothesis in three ways. First antimycin A and TNFa will be used to determine if pharmacological stimulation of mitochondrial ROS release can elicit dilation of human coronary arterioles. In separate studies, we shall use novel antioxidants targeted to the mitochondrial inner membrane to determine whether H2O2 generated from within the mitochondria is necessary for FMD. A bioassay system will confirm whether H2O2 is indeed an EDHF mediating FMD in the human coronary circulation. Second we will use immunohistochemistry and specific pharmacological and molecular approaches including siRNA to determine whether endothelial cytoskeletal elements play a necessary role in FMD and mitochondrial ROS generation. Third, we shall test the hypothesis that nitric oxide through its inhibitory effect on mitochondrial respiration reduces FMD in the human heart. This will be done using nitric oxide donors, measuring mitochondrial complex activity and ROS generation. These experiments may identify a pathway not previously described by which nitric oxide can inhibit EDHF-mediated dilation; namely, by blocking mitochondrial production of ROS. Collectively these aims address a novel mechanism of endothelium-dependent vasodilation involving mitochondrial generation of ROS, thus far reported only in human hearts. These studies should identify new links among cell processes including mechanotransduction, respiration, and redox signaling that regulate physiological events such as vasodilation.

切应力作用于内皮细胞产生血管舒张。这可以说是最具生理学意义的 扩张的重要内皮机制，并发生在几乎每一个血管床。我们的最新数据 实验室表明，冠状动脉粥样硬化患者冠状小动脉中存在血流介导扩张（FMD）， 然而，它是通过一种涉及内皮细胞产生活性氧的新机制来运作的 包括过氧化氢（H2 O2）的活性氧物质（ROS）。令人惊讶的是，线粒体呼吸链发挥着 线粒体在人类心脏中的FMD中起着必要的作用，然而，尚不清楚线粒体如何参与FMD的发生。 在内皮表面上传递机械剪切应力以引起扩张。 我们的总体假设是，剪切力通过附着的细胞骨架元件作用于内皮细胞 刺激线粒体释放H2 O2，一种内皮衍生的超极化因子（EDHF）。我们将 用三种方法来检验这个假设。首先，将使用抗霉素A和TNFa来确定是否具有药理学作用。 刺激线粒体ROS释放可引起人冠状小动脉扩张。在不同的研究中，我们 应使用针对线粒体内膜的新型抗氧化剂，以确定是否产生H2 O2 是口蹄疫的必要条件生物测定系统将确认H2 O2是否确实是一种 EDHF介导人冠状动脉循环中的FMD。其次，我们将使用免疫组织化学和特异性 药理学和分子方法，包括siRNA，以确定是否内皮细胞骨架 元件在FMD和线粒体ROS产生中起必要作用。第三，我们将检验假设 一氧化氮通过其对线粒体呼吸的抑制作用减少了人类心脏中的FMD。这将 使用一氧化氮供体，测量线粒体复合物活性和ROS生成。这些 实验可以确定以前没有描述过的一氧化氮可以抑制EDHF介导的 扩张;即通过阻断ROS的线粒体产生。 总的来说，这些目标涉及内皮依赖性血管舒张的新机制， 线粒体产生ROS，迄今为止仅在人类心脏中报道。这些研究应确定新的联系 在细胞过程中，包括机械传导、呼吸和氧化还原信号传导， 例如血管舒张。